1. Field of the Invention
The present invention relates to dietary fiber, in particular, a porridgelike dietary fiber prepared from beet. It also relates to foods containing such dietary fibers and to a method for producing a porridgelike dietary fiber.
2. Prior Art
With the rapid improvement in the standard of living in recent years, the eating habit in Japan has shifted to luxuries, and the consumption of highly purified or processed foods has increased. As a result, so-called Western-type adult diseases have been increasing.
Since the proposal of Burkitt's hypothesis on the interrelationship between the rectal cancer and meals, many studies have been made on the physiological functions of dietary fiber.
In recent years, dietary fiber has received an increasing attention, and it has been proved that dietary fiber is closely associated in terms of physiology with such adult diseases as rectal cancer, increase in the level of serum cholesterol, arterial sclerosis, diabetes, etc. New functions of dietary fiber have also been found, for example, inhibition of digested or absorbed of toxicity.
Since the recognition of the importance of dietary fiber as a diet factor that affects the human health, various dietary fiber derived from vegetables, root crops, fruits, cereals, etc. has been produced.
In usual cases, dietary fiber products are in the form of powders or granules and prepared by subjecting fibers separated from the above sources to drying, pulverization, classification, etc. Where necessary, the products are additionally subjected to an acid or alkaline treatment and/or bleaching with an appropriate bleaching agent.
The thus prepared dietary fiber products have an expansibility and a water holding property corresponding to their origin, and most of the products are consisted mainly of cellulose, hemicellulose, pectin and lignin.
Beet roots, which have been known as a raw material for sugar, can also be a useful source for dietary fiber, and many methods have been proposed for producing dry powders of dietary fiber from beet roots, wherein sugars and other water-soluble components are removed from the roots by means of immersion into warm water, and the residue is subjected to heating, drying, pulverization and classification (see, e.g., Japanese Patent Publication Nos. Sho 58-8827; Sho 58-20,247 and Sho 63-41,543).
It has also been proved that dietary fiber prepared from beet roots can be excellent in their functions relating to nutritional physiology (see, e.g., Japanese Patent Laid-Open Nos. Sho 61-103,832; Sho 61-155,331; Sho 62-51,623 and Sho 63-216,822).
Because of this, there have been proposed fiber-intensified foods prepared by blending beet root dietary fiber with other food materials since ingesting foods added with such a physiologically excellent dietary fiber contributes to the maintenance of human health by supplementing fibers, which may otherwise be present in foods in only sufficient quantities (see, e.g., Japanese Patent Publication No. Sho 58-34,104).
However, in the hitherto known fiber-intensified food products, dietary fiber prepared from beet roots is blended in the form of dried powder and hence could hardly be distributed uniformly, thus giving a rough mouthfeel to the resulting food products. In addition, food products blended with beet root dietary fiber have a slight unpleasant odor characteristic to beet roots, in particular, at the time when heated.